From The Grindhouse Cinema Database
- The house is Oakley Court, used for exteriors in several Hammer films, and for The Rocky Horror Picture Show (1975). It was later turned into a luxury hotel.
- Rumors abound about a missing scene in which Fran and Miriam are seen inside the caravan of John and Harriet. This rumor is borne out by production stills and a vague recollection by producer Brian Smedley-Aston that it was, indeed, shot.
- The screenplay is credited to Diana Daubeney, director José Ramón Larraz's wife Diana. According to Larraz and producer Brian Smedley-Aston, she didn't actually write a word of it. She was credited because, as a British citizen, she filled a UK production quota.
- Larraz wrote the screenplay in five days.
- The old Magnum Entertainment release contains the above cuts which were removed from the Anchor Bay version. However, the Magnum version is still about a minute shorter than the Anchor Bay release due to some editing during the following sequences:
- The opening title sequence is different on the Magnum version. The original piano music has been replaced by an electronic synthesizer score, and the title sequence consists only of "Lee Hessel presents" and "Vampyres" in red lettering with a stylized 'V' in the shape of two demons. The Anchor Bay version uses the original credits, with plain blue lettering for "Vampyres (c) Essay Films Ltd MCMLXXIV" followed by all the cast and technical credits.
- During the ending sequence, all shots of Ted being discovered in his car and driving off have been removed (approx 55 seconds). The dialogue between the estate agent and the elderly couple has been moved to cover up these cuts.
- Several lines of dialogue between the estate agent and the elderly couple have been removed altogether (from the agent saying "the ghosts of the those two poor women..." onwards).
- After the end cast credits have scrolled up the screen, the Magnum version inserts the technical credit sequence which was removed from the start, with the original music again replaced by a synthesised score. The final credit for the director seems to have been re-done in different lettering and a darker blue.
- Finally, the Magnum version finishes with "(c) MCMLXXIV Essay Films Ltd. All rights reserved" in white lettering on a black background. The Anchor Bay version finishes with "The End. Made by Essay Films Ltd. 185 Great Portland St., London W1, England" over the final shot with the house in the background.